Various technologies are known in the field of building construction. In the housing sector as in the construction of small apartment complexes and other buildings, masonry technologies include the use of portable prefabricated blocks such as cinder blocks and bricks. This conventional technology requires only modest material outlay and is well suited to small construction companies. The use of such materials does not require particular professional training other than that of a mason. Furthermore, the well established performance of such materials reassures the end user, generally conservative by nature.
Masonry blocks must generally possess several characteristics such as:
a light weight in order to be portable, PA1 a high crush resistance, PA1 low thermal conductivity, PA1 mechanical and chemical compatibility with the other materials used in building construction, in particular plasters and surface coatings, PA1 a pleasing surface appearance after finishing, PA1 good fire resistance, PA1 and the lowest possible cost per square foot or square meter of finished wall in the final structure.
The masonry block placed at the base of a wall must resist the permanent load of the building as well as service loads of any elevated floors. It is generally considered that the block must support, without crushing, a compression load of some 435 PSI (3 MPa) while in service in a small building having a ground floor and three elevated floors.
Generally known techniques for the fabrication of masonry blocks associate structural materials of which the least expensive are generally rock based, with insulating materials such as air or any material having gaseous inclusions, in order to obtain a composite material sufficiently insulating and structurally sound. Of the two components one must have binding properties in order to form a support structure. The other may generally be dispersed in the first, as the fabrication of a homogeneous medium on a structural level, having the two materials intimately bound can be a difficult procedure.
The most common masonry blocks, cinder blocks and bricks, most often have vertical or horizontal cavities the purpose of which is to reduce the weight and cost of the block as well as to reduce the thermal conductivity of the wall in which the block will be incorporated. Moreover, modern thermal insulation requirements make necessary the coating of the structure comprised of such blocks with one or more layers of insulating material, resulting in considerably higher cost per square foot of finished wall.
Various other solutions have been proposed such as building walls of families of materials of a vastly different conception such as baked cellular concretes or concrete lightened by the inclusion of polystyrene balls. Such materials, in their dry state, have low thermal conductivities, but it has been noted that their thermal conductivity increases considerably with the percentage of water contained in the concrete. To avoid water intrusion into walls, such materials must be coated with humidity inhibiters, increasing building costs without necessarily precluding the penetration of humidity into the wall in the long term.
It is of course possible to use wood in the construction of small buildings up to several stories high, wood having a low thermal conductivity and a high resistance to compression. However, the primary drawback in the use of wood is its high cost.
The object of the present invention is to provide a masonry block element which overcomes the drawbacks cited in prior art elements, and which is at the same time portable, insulating, structurally sound, chemically compatible with the other materials used in building construction such as plasters and surface coatings, which has a pleasing finished appearance, good fire resistance, and whose cost is relatively modest.